A variety of known ink materials used for printers, printing machines, and markers are classified into water-based inks containing water and water-based solvents, and solvent inks containing non-water-based solvents. Recently, in order to reduce environmental load and negative impact on the health of consumers and printing technicians, switchover to water-based inks has been increasingly required even in fields in which oil-based inks are mainly used. For example, although solvent inks have been commonly used for outdoor displays and signboards, which require long-term weatherability, as well as for printing on recording media that do not absorb water-based inks, such as polyvinyl chloride sheets, switchover to water-based inks that are free from non-water based solvent has been required in such fields.
A variety of printing methods using these inks are also known. Among them, inkjet recording is preferred because of the unnecessity of the fabrication of printing plates, suitability for high-variety, low-volume production, and usage of less ink.
As such water-based inks for inkjet recording, for example, ink compositions containing colorants, lubricants, penetrating agents, and water are known (see, for example, PTL 1).